想象一种从野外消失的动物,然后在一个没人预料到的地方留下了线索。这就是德克萨斯州加尔维斯顿岛发生的事情。2018年发表在《基因》期刊上的一项名为《在美国墨西哥湾沿岸的犬科动物种群中重新发现红狼幽灵等位基因》的研究发现,那里野生犬科动物的DNA中含有红狼的基因。红狼曾被宣布于1980年在野外灭绝。
Imagine an animal that vanished from the wild and then left a clue in a place no one expected. That’s what happened on Galveston Island, Texas. A 2018 study titled ‘Rediscovery of Red Wolf Ghost Alleles in a Canid Population Along the American Gulf Coast,’ published in the journal Genes, found red wolf genes in the DNA of wild canines there. Red wolves had been declared extinct in the wild by 1980.
就连科学家们也对这一发现感到惊讶,因为传统科学一直将墨西哥湾沿岸的红狼目击事件视为误认的郊狼。一个濒临灭绝的物种红狼(Canis rufus)曾遍布美国东南部。它们比郊狼大,但比灰狼小。到20世纪70年代,它们正走向灭绝,许多红狼与郊狼杂交。已知的最后一批红狼被捕获,用于一项旨在拯救该物种的圈养繁殖计划。
Even the scientists were surprised by the finding, because conventional science had dismissed red wolf sightings along the Gulf Coast as misidentified coyotes.A species on the edgeRed wolves (Canis rufus) once ranged throughout the southeastern United States. They are bigger than coyotes but smaller than gray wolves. By the 1970s, they were becoming extinct, and many were cross-breeding with coyotes. The last known red wolves were captured for a captive breeding program in an effort to save the species.
普林斯顿大学的研究新闻报道称,共有240只犬科动物被捕获用于该计划。其中17只被确定为纯种狼,而在这17只中,有14只能够繁殖。北卡罗来纳州于1987年开始重新引入红狼。但该报道指出,截至2018年,野外种群中红狼数量已不足40只,使该物种在野外再次濒临灭绝。邮寄的手术刀这项研究始于野生动物生物学家罗恩·伍滕,他一直在追踪加尔维斯顿岛上的一群犬科动物。
The Princeton University study news report said 240 canines were captured for the program. Seventeen were determined to be pure wolves, and of these, fourteen were able to breed. North Carolina began reintroducing red wolves in 1987. But the report says that as of 2018, the wild population had fewer than 40 red wolves, putting the species once again on the brink of extinction in the wild. A scalpel in the mailThe study began with wildlife biologist Ron Wooten, who had been tracking a pack of canines on Galveston Island.
他给普林斯顿大学布里奇特·冯霍尔特的实验室发了电子邮件,请求对两只被车撞死的动物进行基因检测。冯霍尔特说,她经常收到这类请求。但他的热情和奉献精神显露无遗,一些非常有趣的狗的照片也是如此。后来,第二份样本在途中丢失了,于是伍滕把他用来采集样本的手术刀寄了过去。
He emailed Bridgett vonHoldt’s lab at Princeton, requesting genetic testing on two road-killed animals. vonHoldt says she gets that kind of request often. But his enthusiasm and dedication showed through, as did some very interesting photographs of the dogs. Then the second sample got lost along the way, so Wooten sent the scalpel he had used to take it.
研究人员伊丽莎白·赫彭海默表示,此前从未有人给实验室寄过手术刀,这让提取DNA的过程令人难忘。DNA揭示了什么赫彭海默表示,这一发现非同寻常,因为红狼在该地区已被宣布灭绝超过35年。研究团队将加尔维斯顿的DNA与从阿拉巴马州、路易斯安那州、俄克拉何马州和得克萨斯州采集的29只郊狼的样本进行了比较。
Researcher Elizabeth Heppenheimer said no one had ever sent the lab a scalpel before, which made extracting that DNA memorable. What the DNA showedHeppenheimer said the find was remarkable because red wolves had been declared extinct in the area more than 35 years ago. The team compared the Galveston DNA with samples taken from 29 coyotes in Alabama, Louisiana, Oklahoma, and Texas.
他们还使用了来自黄石公园的10只灰狼、来自安大略省阿尔冈昆省立公园的10只东部狼,以及11只圈养红狼。加尔维斯顿的这些动物在基因上更接近圈养红狼,而非典型的东南部郊狼。它们携带有圈养红狼体内存在、但郊狼和灰狼体内没有的基因。它们还带有一种在已知任何北美犬科动物中都未发现的基因变异。赫彭海默表示,这可能代表着在圈养繁殖过程中丢失的红狼基因。
They also used 10 gray wolves from Yellowstone, 10 eastern wolves from Algonquin Provincial Park in Ontario, and 11 captive red wolves. The Galveston animals were genetically closer to captive red wolves than to typical southeastern coyotes. They had genes found in captive red wolves, but not found in coyotes and gray wolves. They also had a genetic variation found in no known North American canine. Heppenheimer said it may represent red wolf genes lost during captive breeding.
该研究的标题使用了“幽灵等位基因”一词,而等位基因不过是同一基因的不同版本。这意味着什么,又不意味着什么这并不意味着某处隐藏着一群秘密的纯种红狼。研究人员只有照片和从路杀动物身上取得的小块样本可供研究,并未测量任何身体尺寸。赫彭海默承认,这些动物“外表模棱两可”,很可能是因为杂交。狼和郊狼往往只在种群密度非常低时才会杂交。
The study title uses the term "ghost alleles", and alleles are simply different versions of a gene. What it means, and what it does notThat doesn’t mean there’s a secret pack of pure red wolves hidden somewhere. The researchers only had photographs and small samples from road-killed animals to work with and did not measure any body dimensions. The animals were “ambiguous-looking,” Heppenheimer acknowledged, probably because of interbreeding. Wolves and coyotes tend to interbreed only when population densities are very low.
赫彭海默表示,得克萨斯州可能是未来重新引入工作的好地方,但首先需要更多研究。如果重新引入的狼与当地郊狼杂交,这些杂交后代可能有助于恢复丢失的红狼基因。资深作者冯霍尔特表示,美国东南部可能并不存在“标准郊狼”。她说,一些郊狼可能保留了某个已灭绝物种的基因痕迹。赫彭海默与克里斯汀·布热斯基同为第一作者,她将这一发现归功于在当地工作的人们。
Texas may be a good place for future reintroduction efforts, Heppenheimer said, but first more research is needed. If reintroduced wolves interbreed with local coyotes, the hybrids could help restore lost red wolf genes. There might not be a “canonical coyote” in the American Southeast, said senior author vonHoldt. Some coyotes, she said, might retain genetic traces of an extinct species. Heppenheimer, a lead author along with Kristin Brzeski, credited the people on the ground for the discovery.